Tanzanian fog nets – New water tanks ensure reliable water supplies

For more than eight years now, Munich Re Foundation has been supporting projects that harvest drinking water from fog and dew. The German non-profit organisation p(e)d world already began installing fog nets in the Babati highlands back in 2009. As of 2015, two new water tanks are in operation holding 30,000 litres of water.

Fog collectors can deliver precious drinking water to areas with high levels of air humidity. The method is actually remarkably simple and has enormous potential in arid regions. The prerequisite is the enduring and natural formation of fog: the collectors capture the fog thus allowing water drops to form in the nets and then run down into collecting troughs. The fog water harvested in this way is of drinking water quality and can be used immediately.

Bernhard Küppers and Christina Bösenberg from p(e)d world e.V. have been supervising school projects in Tanzania since 2008. In 2009 they also began to take care of drinking water supplies to the schools. The construction of conventional wells is not possible in the Babati region. The drinking water at the water points is often polluted and muddy. Children – above all girls – must set out on a daily trek of several hours to fetch water. The conditions for harvesting fog in the region are ideal. Night for night, thick fogs form above a series of salt lakes and rise along the continental rift of Africa. Thermal winds propel the fogs onto the plateaus at altitudes of 2000 metres. This is where the collectors are installed.

Drinking water for five schools

The p(e)d world project organisers first installed small test collectors. The water yield was measured at ten different locations for one year and then the project was able to begin. In 2010, the first four double collectors with a net surface area of 80 square metres each were set up at two schools in Qameyu and Umagi. In 2013, with the help of Munich Re Foundation funding, seven more collectors were built at three schools. Almost 1,700 pupils now benefit from the fog water. Another double collector is located in the village of Daraja la Mungo. It supplies the village residents.

Water tanks for reliable supply

The production of drinking water alone is not enough. It is at least as important to store the water for times when there is no fog. Until now, black plastic containers have been used in Tanzania as collecting vessels. However, they are not made of food-grade material and stand beside the fog nets in the direct sunlight. The water can only be stored in these containers for a few days, as the water quality begins to deteriorate very quickly.

For this reason, the p(e)d world project managers decided to build two large water tanks with a capacity of 10,000 and 20,000 litres at the Qameyu and Umagi schools. Local building companies began work in August 2015 and everything went without a hitch. The water tanks were checked by water engineers from the Babati regional government in November 2015 and were approved without restriction. Munich Re Foundation supported the measure with funding.

Huge demand Unfortunately, the fog water harvested in Qameyu and Umagi is still not enough. Every day, over 500 pupils must be supplied in each of the schools. The demand for drinking water is immense. The project managers therefore decided to also collect the rainwater from the roofs of the schools (rainwater harvesting) and fill it into the tanks. Almost all the school buildings were fitted with drain pipes and roof gutters. In Umagi, a filter system was also installed to ensure the high quality of the water.

All these measures bring about sustainable improvements to the living conditions of the school children in Qameyu and Umagi. Although the water and storage capacities are not yet quite sufficient enough to provide the schools with water for the whole year, the small project successes are worth the effort: they show how important it is to keep on working at improvements.